Nevirapine

Floating drug delivery system is suitable for NVP as the absorption and solubility of NVP is high at pH

The purpose of the study was to formulate floating alginate beads of Nevirapine (NVP), an Anti-HIV agent. Inspite of long half life (45 hrs) a Nevirapine controlled release once daily formulation could be used to maintain optimum peak plasma concentration for effective viral suppression. The floating bead formulations were prepared by dispersing Nevirapine together with Sodium bicarbonate in a mixture of sodium alginate and Hydroxypropyl methylcellulose solution and sunflower oil and then dripping the dispersion into an acidified solution of calcium chloride. Calcium alginate beads were formed, as the alginate underwent Emulsion gelation by calcium ions, and carbon dioxide developed from the reaction of carbonate salts with acid. The obtained beads were able to float due to CO2 -gas formation and the gas entrapment by the polymeric membrane. The prepared beads were evaluated for percent drug loading, drug entrapment efficiency, morphology, surface topography, buoyancy, in-vitro release, and release kinetics. The beads containing higher amounts of calcium carbonate demonstrated an instantaneous, complete, and excellent floating ability over a period of 24 hours. And this floating beads are compared and evaluated with Nevirapine floaing gel, Good floating properties and sustained drug release were achieved. Finally, these floating beads seemed to be a promising gastro retentive drug delivery system.

An accurate, precise and reproducible high performance liquid chromatographic method was developed for the simultaneous estimation of lamivudine, zidovudine and nevirapine in pharmaceutical dosage forms. Phenomenex C18 column (250 x 4.6 mm; 5µ) was employed for the separation of drugs. A mixture of 0.02 M trichloroacetic acid (6.8 pH) and methanol in the ratio of 40:60 v/v was used as the mobile phase and pumped at a flow rate of 1ml/min. The detection wavelength was set at 265 nm. The linearity of quantification was observed in the range of 7.5-112.5, 10-150 and 15-225 μg/ml for lamivudine, zidovudine and nevirapine respectively. The proposed method was validated according to ICH guidelines. The method was found to be suitable for simultaneous and accurate determination of these drugs in tablet dosage forms without any interference from the excipients.